Tuesday, 19 August 2008

Math Challenge 9

Think of a number (Keep the number to yourself).

Add five to it.

Multiply the total by two.

Subtract the original number twice.

Is the answer "TEN"?

Thinker: How is it done?



sourav said...

Very Easy...xelect X instead of any no and then it will be very clear...

rara said...

yes, in connection to what sourav said, 2 have been distributed to the your number and to five:
2(x+5) = 2x+10
then subtract twice your number (2x) again from the resulting expression (2x+10).. leaving '10'

2x+10-2x = 10